Background: Besides standard periodontal procedures, additional approaches, including medication, laser therapy, and photodynamic therapy are employed to manage excessive inflammation and pathological reactions. The present study aimed to evaluate laser and photodynamic therapy (PDT) as complementary treatments for periodontitis.Materials and Methods: This clinical trial enrolled 12 patients (30-60 yrs.)With periodontitis stages I and II. Following initial treatment, one quadrant served as the control, one treated with a diode laser, and the other one with Photosan wavelength power with methylene blue dilution. Clinical variables including bleeding on probing (BOP), pocket depth (PD), and clinical attachment level (CAL) were measured and surveyed. Also, samples from gingival crevicular fluid were taken at 2 and 6 weeks for evaluation. The data collected were analyzed using the Friedman test, ANOVA, Kruskal-Wallis, and LSD post-test.Results: The mean bacteria levels in all three treatment groups were significantly reduced (P < 0.001). There were no significant differences in P.g and P.i bacteria (P > 0.05) in all three treatment methods. A.as was notably reduced at 6 weeks (P = 0.037). CAL and PD significantly decreased in all three treatment groups (P < 0.001), with no statistically significant difference between the treatment methods (P > 0.05). The mean BOP significantly decreased in the laser therapy (P < 0.001) and PDT groups (P < 0.002).Conclusion: This study found that diode laser therapy and PDT can effectively reduce periopathogens, particularly A.a, and improve clinical signs in patients with periodontitis stages I and II. تفاصيل المقالة